Question about outlet orientation

Okay I am a little confused. Which way is the plug receptacle supposed to be installed, round ground plug up or down? In most every building I've been in, including new construction, the ground plug is down. Yet it many professional electrical publications I've seen, including a manual I bought, they are installed opposite with the ground up. Does it matter?

 

For an industrial setting, where they use metal cover plates, ground up is considered safer - should something be plugged in and the metal cover plate falls down, then it would touch the ground pin on the plugged in plug and stop - cover plate would not become energized.

Otherwise MANY extension cords/power strip plugs are designed to be plugged in with the ground prong down. The the wire goes down toward the floor. Like this...
https://i5.walmartimages.com/asr/0a5...6f595c827.jpeg

I have mine installed in my house with the ground prong down as many of the things I plug in expect it to be that way. Also I have non-electrically conductive plastic cover plates.

 

It really doesn't matter. There is no code rule for this.

 

Bill nailed it on the why one typically installs with the ground plug up. Personally, I don't like that look and install with it down. As pcboss said, either is compliant with code.

 

Ok, now lets talk horizontal mounting!

Lol, this same thing comes up every few years. Same answer every time. "It doesn't matter".

 

We've got a local electrician who insists that ground plug up is "the way it's supposed to be". I tend to agree that heavy cords hold better in this position, but it still drives me nuts. I think he likes doing it cuz it's like his "calling card" that he did the wiring there... since he's the only one that dies it that way.